The invention relates to an configuration for triggering restraining devices in a motor vehicle. The configuration has, a sensor device with a pair of linear acceleration sensors for triggering the restraining devices.
Such a configuration is known from Published, European Patent EP 0 686 533 A1. In that reference, a sensor device has two acceleration sensors whose sensitivity axes are disposed offset by +/xe2x88x9245xc2x0 with respect to the longitudinal axis of the vehicle. The acceleration signals which are supplied by the acceleration sensors are evaluated in an evaluation circuit. As a function of the acceleration signals and of a seat-occupation detection device a triggering signal is generated for one or more selected restraining devices by a triggering circuit in accordance with the direction and strength of the impact.
In order to detect roll-overs in a motor vehicle, Published, Non-Prosecuted German Patent Application DE 44 36 379 A1 proposes an angle of inclination sensor which contains two acceleration sensors which are orientated differently with respect to one another and whose sensitivity axes are disposed in the plane of inclination.
German Patent DE 41 14 992 C1 discloses an angle of inclination sensor with a V-shaped hollow profile. Electrodes on the hollow profile walls serve to detect a change-in position of a mass element disposed in the hollow profile.
German Patent DE 37 05 920 C2 proposes an acceleration sensor for sensing accelerations in three spatial directions, which sensor has three coils which are offset with respect to one another by 90xc2x0 and within which a magnet is cardanically mounted.
So-called local impacts, in which the vehicle suffers an impact which is offset with respect to the longitudinal axis or transversal axis of the vehicle, are the type of accident which occurs frequently in road traffic. Local impacts are typical of the collision of two vehicles at intersections, of accidents when a vehicle is overtaking or of accidents when a vehicle is moving back,into the flow of traffic after an overtaking procedure. In such accidents, the vehicle skids or rotates about its own vertical axis. It may be necessary to trigger selected restraining devices to provide the best possible protection to the vehicle occupants without, however, the linear acceleration sensors supplying acceleration signals which would lead to triggering.
It is accordingly an object of the invention to provide a configuration for triggering restraining devices in a motor vehicle that overcomes the above-mentioned disadvantages of the prior art devices of this general type, which protects a vehicle occupant as well as possible during any conceivable type of impact/accident.
With the foregoing and other objects in view there is provided, in-accordance with the invention, a configuration for triggering restraining devices, including: a sensor device having two acceleration sensors with differently orientated sensitivity axes and outputing acceleration signals, the sensor device also having a rotational movement sensor for detecting rotational movements about a vertical axis of a vehicle and outputing a rotational movement signal; an evaluation circuit for receiving and evaluating the acceleration signals and the rotational movement signal generated by the sensor device and outputing an evaluation signal; and a triggering circuit receiving the evaluation signal from the evaluation device for generating a triggering signal for a restraining device, the triggering signal generated in dependence on the acceleration signals and the rotational movement signal.
The sensor device of the configuration has the rotational movement sensor for detecting rotational movements about the vertical axis of the vehicle. In this way, skidding movements of the vehicle can be detected. A triggering signal for at least on restraining device is generated as a function of the acceleration signals of the linear acceleration sensors and the rotational movement signals supplied by the rotational movement sensor.
The configuration according to the invention provides the vehicle occupant/occupants with the best possible impact protection, both linear accelerations and rotational movements being detected by the sensor device and contributing to a triggering decision.
Preferably, the restraining devices to be triggered in the event of an impact are selected from the totality, or at least from a number, of restraining devices as a function of the acceleration signals and the rotational movement signal.
In accordance with an added feature of the invention, the sensor device has a further rotational movement sensor for detecting rotational movements about a longitudinal axis of the vehicle and outputs a further rotational movement signal, the triggering signal generated in dependence on the further rotational movement signal.
In accordance with an additional feature of the invention, the sensor device has an additional rotational movement sensor for detecting rotational movements about a transverse axis of the vehicle and outputs an additional rotational movement signal, and the triggering signal generated in dependence on the additional rotational movement signal.
In accordance with another feature of the invention, the restraining device is one of a plurality of restraining devices, at least one of the plurality of restraining devices has at least two stages that can be activated and have different protective effects for an occupant of the vehicle, and the triggering circuit selecting a suitable protection level of the plurality of restraining devices in dependence on the acceleration signals and the rotational movement signal.
In accordance with a further added feature of the invention, there is a common control unit mounted in a central region of the vehicle and housing the sensor device, the evaluation circuit, and the triggering circuit.
In accordance with a concomitant feature of the invention, the triggering circuit determines and generates a timing signal for a triggering time in dependence on the acceleration signals and the rotational movement signal, the restraining device is one of a plurality of restraining devices that are triggered only if the timing signal for the triggering time and the triggering signal are simultaneously present at a respective restraining device.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a configuration for triggering restraining devices in a motor vehicle, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.